Slow drains? It may be clogged pipes.

It’s only a matter of time before you experience clogged pipes in your home’s plumbing system. Eventually, one or multiple pipes in your home will become plugged. Because pipes leading the wastewater out and away from the home are usually concealed beneath the floors and inside of the walls, it can be difficult to tell what is causing which pipe to back up.

One of the most common calls St Paul Pipeworks plumbers get is from customers reporting that a floor drain has started to back up. Often, the whole main line is plugged, but when one thing starts to back up, the first place that the backup starts to appear is in the floor drain because it is the lowest opening in the house.

Understanding the Challenge of Clogged Pipes

When the main line in your home begins to plug up, the clog is usually not near the drain or fixture where you start to see it. It is usually located down the line 10 or 15 or even 20 feet away, so when you start using that pipe, it hits that clog, and the water starts backing up. Eventually, it will show up in the first used fixture down the pipeline, usually the floor drain.

The same thing can be true if you have a basement bathroom and a main-floor bathroom. For example, you can plug up just the basement bathroom.

If that is the case, you could still use all of the other fixtures in the house without the basement bathroom pipe backing up any further. They would do their jobs normally and the waste pipe would work. But once you start using the fixtures in the basement bathroom and it keeps backing up further, you know that you have at least that bathroom backed up.

When St Paul Pipeworks plumbers go out to clear any drains, the first thing we do is figure out if there is more than just the one fixture that is plugged up. Usually, the main lines are less likely to plug up because they are larger in size, but it does occasionally happen.

Professional plumbers call this process isolation; the plumber tries to isolate what is causing the clog and where it is located. It is something that a homeowner can troubleshoot. If they visualize what pipes are located there and try eliminating a few options, they can sometimes tell if it is just a fixture or if it is just a fixture group, or if it is the whole main line.

What can a homeowner try to do to determine where the plug-up is located?

If you start with the first example, where the floor drain has started to become plugged, St Paul Pipeworks plumbers would recommend having the homeowner flush the main floor toilet many times in a row – flush it and let it fill all the way up, flush it again and let it fill up.

Flush it again 3 or 4 times. If you start to see that water is coming up in that floor drain, then you know that you have a main line plug up. If nothing shows up from that activity, then you know that that group is isolated from the problem.

Isolating the Culprit – A Plumber’s Approach

The easiest way for professional plumbers to figure out where the clog is located is to add water to force it to keep backing up more. The advantage that a plumber has is that they can visualize how the pipes are situated and what they look like beneath the floor and inside of the walls.

They know, based on where the fixtures are located and where the cleanouts are located, where those pipes are, so it makes it much easier for them to figure out than someone who has never installed any piping.

If you need help with a backed-up pipe or multiple pipes in your home or are just looking for a quality professional plumber in the St. Paul and Minneapolis metro area, give St Paul Pipeworks a call today.

Yours Truly,

Matthew Dettwiler

Social Media Manager


Q: What causes pipes to become clogged?

A: Pipes can become clogged due to various reasons, including the accumulation of debris, grease, hair, and other materials over time.

Q: Are main line blockages common?

A: Main line blockages are less common than smaller fixture blockages due to their larger size. However, they can still occur, causing significant disruptions.

Q: Can I use chemical drain cleaners to clear blockages?

A: While chemical drain cleaners might provide temporary relief, they can also damage pipes and are often ineffective for severe blockages. It’s best to consult professionals for a thorough solution.

Q: How can I prevent future blockages?

A: Regular maintenance, proper disposal of waste, and avoiding pouring grease down the drain are some preventive measures you can take to minimize the risk of blockages.

Q: Is plumbing expertise necessary for DIY troubleshooting?

A: While homeowners can do some basic troubleshooting, plumbing expertise is crucial for accurately diagnosing and resolving complex blockages to prevent further damage.


Plugged pipes can disrupt your daily routine and cause inconvenience. Still, with the expertise of St Paul Pipeworks plumbers, you can regain control over your plumbing system. From isolating the source of the blockage to providing efficient solutions, their team ensures that your pipes are clear and flowing freely.

Whether you’re facing a single fixture blockage or a more extensive main line issue, St Paul Pipeworks is your go-to partner for reliable and effective plumbing services in the St. Paul and Minneapolis metro area. Don’t let plugged pipes get you down – send us a message on our CONTACT FORM or GIVE US A CALL today for a hassle-free solution.

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